Conventional touch devices can be generally categorized into resistive, capacitive, optical, sound wave, and electromagnetic designs. In recent years, touch devices have been widely used in many electronic devices such as mobile phones, computer display panels, touch screens, satellite navigation devices, digital cameras, etc. In conventional capacitive touch devices, the point on the display panel touched by a finger is detected by detecting the change in the capacitance of the capacitor coupled with the finger through a touch sensing electrode. The conventional touch devices can only detect a two-dimensional location of a touch event, and are unable to detect a third dimension of the touch event, i.e. a pressure applied by the touch.